#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<vector>
using namespace std;
int main()
{
	vector<int> vec;
	cout << vec.size();
	vector<int> a{ 1,2,3,4 };
	a.push_back(6);
	vector<int> b = a;
	return 0;
}